摘要
棕色固氮菌固氮酶 FeMo 蛋白与过量(5-6个当量)的酸性靛蓝保温30—60分钟后,蛋白中的 P-金属原子簇全部氧化,然而蛋白中的 FeMoCo 全都处于还原状态。Na_2S_2O_4使这种部分氧化的 FeMo 蛋白中的 P-cluster 重新还原,甲基紫精可加快这种还原。而亚甲蓝等氧化剂则使这种蛋白中的 FeMoCo 受到氧化。对这种部分氧化的 FeM。蛋白分别进行 CD 还原滴定和测定氧化过程中 EPR/ABS 的变化已经得到 P-cluster 和 FeMoCo 的氧化还原当量数目。
After nitrogenase FeMo protein from A.vinelandii was incubated with a large excess (5—6 equivalents) of indigo carmine for 30—60 min.,all of P-clusters in the partially oxidized FeMo protein were oxidized,but all of FeMoCo in the protein were still in the reductive state.The oxidized P-clusters in the protein were able to be completely reduced by Na_2S_2O_4(DT)and the reduction was accelerated by methyl viologen (MV).And all of FeMoCo in the protein were firstly oxidized by some oxidants such as methylene blue.The numbers of the redox equiva- lent of P-cluster and FeMoCo have been obtained by the CD reductive titration of and EPR/ ABS time course on the oxidation of the partially oxidized FeMo protein,respectivelly.
